What Rights Does HMRC Have to Safeguard for the Taxpayer?

Posted: 24th March 2026

When HMRC opens an enquiry or investigation, it’s easy to feel that the balance of power sits entirely with the tax authority. However, HMRC operates within a framework of legal obligations and customer rights designed to ensure fair treatment throughout the compliance process.

As advisers, understanding these rights and knowing when HMRC has overstepped is essential to protecting your clients effectively. This guide sets out the key safeguards that HMRC must uphold and how they apply in practice.

HMRC’s Charter

The HMRC Charter sets out what taxpayers can expect from HMRC and what HMRC expects from taxpayers. First published in 2009 and updated periodically, the Charter is not merely guidance. It is a legal requirement under the Finance Act 2009, and HMRC must operate in accordance with its principles. The Charter establishes that HMRC will:

Respect you – Treat every taxpayer with courtesy and consideration, taking account of individual circumstances.
Help and support you to get things right – Make it as easy as possible to understand obligations and get tax affairs in order. This includes providing clear guidance, tools, and support.
Treat you as honest – Assume taxpayers are honest unless there is evidence to suggest otherwise.
Treat you even-handedly – Apply the same rules and processes to all taxpayers in similar situations.
Be professional and act with integrity – Operate to high standards of behaviour and decision making.
Tackle people who deliberately break the rules and challenge those who bend the rules Take action against non-compliance while ensuring processes remain fair.
Protect your information and respect your privacy – Handle personal and business information securely and only use it for legitimate purposes.
Accept that someone can represent you – Recognise the role of agents and work with them throughout the compliance process.
Do all HMRC can to keep the cost of dealing with them as low as possible – Minimise burden and unnecessary costs where possible.

While these principles might appear broad, they create enforceable expectations about how HMRC should conduct enquiries, respond to correspondence, and interact with taxpayers and their advisers.

Key rights during HMRC enquiries

Beyond the Charter, taxpayers have specific procedural rights throughout HMRC compliance work. Understanding these rights helps advisers identify when HMRC has acted outside its remit or failed to meet its obligations.

Clear communication

HMRC must explain why they are opening an enquiry or requesting information. While they are not required to share their full reasoning or intelligence, they should provide enough context for the taxpayer to understand the nature of the enquiry and what is being examined.

When HMRC issues information notices, they must clearly state what is being requested, the timeframe for response, and the legal basis for the request. If the scope of an information request appears excessive or unclear, taxpayers have the right to seek clarification or challenge the notice.

Reasonable timeframes

HMRC must give taxpayers reasonable time to respond to requests for information or to prepare for meetings. What constitutes “reasonable” depends on the complexity of the request, but HMRC should take into account personal circumstances such as illness, bereavement, or periods when key personnel are unavailable. If HMRC imposes unrealistic deadlines, advisers can request extensions. Where HMRC refuses, this can form part of a formal complaint or be raised during any subsequent appeal.

Representation

Taxpayers have an explicit right to appoint an agent to act on their behalf. HMRC must recognise this representation and direct correspondence and enquiries to the appointed agent where authorisation has been granted. There are also situations where taxpayers can nominate someone other than a professional agent to represent them during meetings or correspondence. HMRC should accommodate this where the request is reasonable.

Privacy and proportionate investigation

HMRC’s powers to request information are broad, but they are not unlimited. Information requests must be reasonable and relevant to the tax position under enquiry. HMRC cannot conduct “fishing expeditions” where they request large volumes of information without a clear connection to a specific tax issue.

Taxpayers can challenge information notices on the grounds that they are overly broad, unduly onerous, or not relevant to the matter under investigation. In some cases, independent tribunal approval is required before HMRC can compel the production of certain types of information. HMRC must also handle personal and business information in accordance with data protection laws. Information gathered during an enquiry should only be used for legitimate tax purposes and must be stored securely.

Fair treatment and consistent application of the law

HMRC is required to apply tax law consistently across all taxpayers. If similar cases are being treated differently without justification, this can form the basis of a challenge. The principle of “treating you as honest” means that HMRC should not assume dishonesty or fraud without supporting evidence. Where HMRC alleges deliberate behaviour, they must be able to point to facts that support this conclusion rather than relying on assumptions or suspicion.

Independent review

If a taxpayer disagrees with an HMRC decision, they have the right to request a formal review by a different HMRC officer. This review must be conducted independently of the original decision maker. Where the dispute cannot be resolved through internal review, taxpayers have the right to appeal to a Tax Tribunal. The tribunal system provides an impartial forum for resolving tax disputes, and HMRC cannot prevent a taxpayer from exercising this right.

Alternative Dispute Resolution

HMRC offers Alternative Dispute Resolution (ADR) as a way to resolve disputes without the need for tribunal proceedings. ADR involves an independent HMRC facilitator who was not involved in the original decision. Taxpayers have the right to request ADR at any stage of a dispute, although HMRC may decline in certain circumstances such as where the issue involves a point of law that requires tribunal determination, or where one party is not engaging constructively.

Complain

If HMRC fails to meet the standards set out in the Charter, taxpayers have the right to make a formal complaint. HMRC has an internal complaints process, and unresolved complaints can be escalated to the Adjudicator’s Office, an independent body that examines complaints about HMRC’s handling of cases. In cases of serious failings, taxpayers may also be able to refer matters to the Parliamentary and Health Service Ombudsman.

Where HMRC powers are limited

While HMRC has extensive powers to investigate tax affairs, there are important limitations on what they can do and when they can act.

Time limits for enquiries

HMRC must generally open an enquiry within 12 months of the filing of a tax return. If they miss this window, they lose the right to enquire into that return unless special circumstances apply, such as discovery of new information suggesting a loss of tax due to careless or deliberate behaviour.

Even where HMRC can make discovery assessments, there are time limits. For careless errors, HMRC generally has six years from the end of the relevant tax year. For deliberate errors, this extends to 20 years. These time limits are strict, and assessments raised outside the permitted windows can be challenged.

The need for reasonable grounds

HMRC cannot open a Code of Practice 9 (COP9) investigation without reasonable grounds to suspect fraud. Similarly, they cannot apply for certain types of information notices or search warrants without demonstrating to a tribunal or magistrate that there is a justified basis for the request. Where HMRC has acted without reasonable grounds, any subsequent assessments or penalties may be vulnerable to challenge.

Protection against oppressive conduct

HMRC is expected to conduct enquiries proportionately and without unnecessary disruption to the taxpayer’s life or business. Behaviour that could be characterised as harassment, intimidation, or oppressive use of powers can be challenged through the complaints process and, in extreme cases, through judicial review.

When do these rights matter most?

Understanding these rights is one thing. Knowing when and how to assert them is another. Here are some common scenarios where taxpayer rights become particularly relevant.

Overly broad information requests

HMRC asks for five years of bank statements, credit card records, and personal correspondence when the enquiry relates to a single claim for relief on a property disposal.

The right to challenge: Information requests must be proportionate and relevant. In this scenario, an adviser might push back by asking HMRC to clarify how the requested information relates to the specific issue under enquiry, and suggest providing more targeted documentation instead.

Unrealistic deadlines

HMRC issues an information notice requiring a complex response within 30 days, despite knowing the taxpayer is recovering from surgery.

The right to request extensions: HMRC must take personal circumstances into account. An adviser can request an extension based on the taxpayer’s health and the complexity of the information being requested. If HMRC refuses unreasonably, this can form part of a complaint.

Assumptions of fraud without evidence

HMRC categorises careless behaviour as deliberate without adequate justification.

The right to challenge categorisation: Advisers can require HMRC to set out the factual basis for their conclusions. If the evidence does not support a finding of deliberate behaviour, this should be challenged robustly, as the categorisation has significant penalty implications.

Failure to consider ADR

A dispute has reached an impasse, but HMRC refuses to engage with ADR without providing clear reasons.

The right to escalate: Where HMRC refuses ADR unreasonably, this can be raised through the complaints process or noted in any subsequent tribunal proceedings as evidence that HMRC failed to engage constructively in dispute resolution.

What advisers should do

When representing clients during HMRC enquiries, advisers should:

Know the Charter and taxpayer rights. Familiarity with these protections allows you to identify when HMRC has overstepped or failed to meet its obligations.
Challenge disproportionate or unreasonable conduct. Pushing back on overly broad information requests, unrealistic deadlines, or unsupported allegations of fraud is not obstructive. It is ensuring your client receives fair treatment.
Document everything. Keep clear records of all correspondence, requests, and HMRC conduct throughout the enquiry. This creates an evidence trail if you need to escalate through complaints or tribunal processes.
Use the complaints process when appropriate. If HMRC is failing to meet Charter standards, a formal complaint can be an effective way to reset the approach to a case.
Seek specialist support when needed. Complex disputes, particularly those involving allegations of fraud or significant penalties, benefit from specialist input. Knowing when to bring in additional expertise protects both your client and your professional position.

Conclusion

HMRC has significant powers, but those powers are not unlimited. Taxpayers have enforceable rights throughout the compliance process, from the initial enquiry through to tribunal proceedings. The HMRC Charter, procedural safeguards, and the right to independent review all exist to ensure that tax investigations are conducted fairly and proportionately.

As advisers, understanding these rights and asserting them where necessary is a core part of protecting clients during HMRC enquiries. HMRC should be challenged when they overstep, when they fail to meet Charter standards, or when they make unsupported allegations. Doing so is not confrontational. It is ensuring the process operates as it should.

If you are managing a case where HMRC’s conduct raises concerns, or if you are uncertain whether your client’s rights are being respected, we are always happy to discuss the situation confidentially.